Retractable landing gear for toy airplanes



July 15, 1952 H. H. SHARP RETRACTABLE LANDING GEAR FOR TOY AIRPLANES Filed July 11, 1947 Patented July 15, 1952 UNITED l STATES PATEN RETRACTABLE LANDING GEAR FOR TOY AIRPLANES v.

Harold H. Sharp, La Porte, Tex. Application July 11, 1947, Serial No. 760,415 7 J wind resistance is lessened, which tends to increase the speed of the plane and the ease of control of the performance of the plane.

A difliculty with this mode of operation, however, resides in the fact that when the operator of the model plane desires to bring the plane in, it is necessary that the plane make a belly landing.

The present invention is directed to the landing gear mechanism, which is controlled by the manipulation of the elevator controls which are used to control the flight of the plane.

An object of the present invention is to provide a landing gear which is operable to retract wheels in flight and operable to lower the wheels before landing.

Another object of the invention is to provide a landing gear mechanism, which mechanism is operable at will by the operator to raise and lower the wheels of a toy airplane. I

Still another object of th invention is to provide a construction which is positive in its action,

yet simple in operation.

A further object of the invention is to provide in a toy airplane a landing gear mechanism which is easily manufactured, of simple construction, but which is durable. V

A still further object of the invention is to provide a landing gear mechanism for a toy airplane which mechanism has a minimum of moving parts and which is relatively easy to install in the model airplane.

A further object of the invention is to provide a landing gear for model airplanes which is operable by the elevator controls which control the flight of the plane, the mechanism being operable during flight of the airplane or at any time the operator so desires.

Other and further objects and advantages of the invention will become readily apparent from the consideration of the following des ption and drawings, wherein:

Fig. l is a top plan view showing the preferred Claims. (CI. 46-77) 2 v embodiment of the landing gear mechanism and its relationship when thewheels are retracted.

Fig. 2 is a. front elevation of the construction and its relationship when the wheels are lowered. Fig. 3 is a modified form of a construction shown in Fig. ,1. V Fig. 4 is an enlarged view to more clearly illustrate the construction of the mechanism. w

In Fig. 1 the mechanism is shown generally at 2. A rubber band 3 'is secured to the 'endfdfiof a crank 5 which crank is rotatably mounted at 6 in a beam 1 of the airplane. The crank 5 is connected to a rock lever'j8 by means of the link 9 secured at 10 on the [crank end of'the-crank 5 and at l2in the eye l3 of the rock lever 8. The

rock lever 8 is pivotally secured at I4. The'gock lever 8 is connectedjto the wheel assemblies l6 which comprise the rods l5,.the crank heads l1, which heads rotate the rods 18 to move a wheel support [9 andwheels 20. I

A stop rest or bell lever 20 pivotallymounted at 22 adjacent a crank end ID of the crank 5 is provided with an eye 2 I to which the elevator controls 23 and 24 are secured; Elevator controls 23 and 24 are control lines leading to the ground and their direction is changed by means (not shown), so that they extend laterally fromflthe plane. For the purposesof this description control line 23 may be designated the up? control line and control line 24 as the down control line. Normally the crank end 10 of the crank 5 will be in engagement with the stop rest, 20'. The latter will have connecting means .(not shown) extending to conventional elevators, In normal operation of the plane this will be a sliding engagement. However, by moving the stop rest 20' bymeans of the elevator controls 23 and 24 beyond a predeterminedposition, the crank end [0' of the crank 5 may be disengaged from such rest so that it rotates through 180 and contacts the other side and end of the stop rest 20'. As the crank end ,lfl' moves through. this arc of 180 the link ,9 is moved-thereby pivoting. the rock lever 8 which in turn moves the rod l5,.-.the crank ends I1 and the wheels .20, whereby the wheels will be moved to or from retracted .position.

Itseems obvious that so-long as tension remains in the rubber band or other mechanism which tends to rotate the cranki, thewheels. maybe retracted or lowered any number of times.

Fig. 3 shows an alternate construction wherein a spring 30 is secured at 3| to the rocklever .8 and at 32 to support structure inthe-"airplane which spring is used in cases'where the wheels T o lc-i:

of the airplane are unusually heavy. That is to say, the ordinary action of the landing gear mechanism might not be strong enough to raise heavy wheels once they are lowered. Therefore, the spring 30, which is positioned so that it normally tends to retain the wheels in retracted position is provided so that when the mechanism is actuated to raise the wheels, additional support will be obtained from the spring.

While'fithe operation 'of the invention seems apparent from the foregoing, by Way of a summary and further explanation, it will be assumed that the airplane is traveling along the ground prior to take off. When the plane'reaches'. the desired speed for take off, the operator will'give a hard down pull on one of the control-strings. This hard down movement of the 7 control string disengages the end ID of the crank' 5from the stop rest or bell lever 20 and the rubbenband causes the crank to rotate, actuating the mechanism so. that the wheels are retracted.

"If for any reason it'is desired toLlower the wheelsjit is only necessary' for the operator to give a hard up,pull on the elevator control string which manipulates the elevators of the airplane to cause it to descend. When this is done, the stop rest 20 is moved-angularly in-the opposite direction so that the crank end l again disengages'fromthe stop. rest 20.and.-ro'- tates .another.180.' This actuates the rods l to lower the wheels to a landing position. While the "foregoing has referred to a hard fdown". and up for retraction and lowering. the landing gear respectively, it is of course .apparentithat the control string movement. could be reversed although that described is deemed preferable." Reverse control couldreadily be obtained by reversing the pivot connection of the rods to the rock lever 8.

A lever 35 is provided, extending. rear-wardly. to control a tail wheel if oneisused, or. it may be hooked up; to a throttle-control and to'control the flaps if vso desired.

.A'. construction in accordance with. this invention is not limitedfin its. operationby the speed of 'the' airplane, nor is it necessary that an additional string beusedtocontrol the. mechanism. Thetwoelevator wires thatare used to control the flight of the plane serve as a meam" by which the mechanism is actuated to either retract or lower the wheels.

T'Broadly the invention contemplates a. landing gear' mechanism .for. model airplanes, which mechanism is operable .at will bythe operatorby manipulation of thefelevatorcontrols.

'jThe inventionclaimed is:

'1. A retractable landinggear. mechanism. for toy airplanes operable by control 1 lines, .comprising, a crank rotatably mounted in the, plane, means connected therewith tending to .rotate said crank, a' rock lever pivotally mounted in the plane, a link connecting said crank and said lever, rods connected to said lever and extending laterally thereof, crank head endsconnected to the ends of said rods,'wheel supports connectedto 'said-crankheada'wheels mounted on said supports, a bell lever pivotally mounted adjacent the crank end of said crank, said control lines being operatively'connected to said bell lever, said bell lever being normally engaged with said crank but movable .by the control. lines whereby, said crank rotating means rotates said crank through 180 whereby'said. link. pivots said rock lever to move saidllaterally extending rods to raise and lower said wheels.

2. A landing gear mechanism for toy airplanes operable by control lines to raise and lower the wheels at will, comprising, a crank rotatably mounted in said airplane, means to rotate said crank, a rock lever pivotally mounted in said plane and linked with said crank, rods extending laterally from said rock lever, wheel supports connected on the ends of said rods, a bell lever pivotally mounted adjacentsaidcrank and nornally engaged therewithgsaid control lines being operatively connected to said bell lever, said fitbell lever being movable by the control lines to disengage it from said crank whereby said means :"rotatessaid'crank through substantially to wheels of the airplane at will, comprising, a crank rotatably mounted in said plane, means to rotate said crank, a rock lever pivotally mounted in said plane andconnected to said crank, rods connected to said rock lever and e rtendinglaterally therefrom,.wheels connected to said rods," means normally-engaged with said. crank butmovable by the control lines .to disengage the crank whereby said. crank. rotating means ,mov'es said crank to raise and lower said wheels. v,

4. A landing gear mechanism for toy airplane operable by; control lines, comprising, a crank shaft rotatably mounted insaid plane, means connected thereto tendingto'. rotate said'crank, a stop rest pivotally .mOunted adjacent said crank and normally engaged therewith, said.control linesbeing operatively connected tosaid, stop rest, a pivotplatelinked with saidcrank, wheel assemblies connected to said pivot .plate,-wheels connected to said wheel assemblies, said stop rest,beingmovable b the control lines. to disen: gagexsaid restffrom said.'crank so that thecrank rotating means moves said crank through 180 and. re-engages. said rest, the rotation of .said crank movingsaid pivot plate whereby said wheel assemblies-are moved to raise-and lower said wheels. a,

5. In a toyairplane; a landing gear mechanism operableto raise and lower the-wheels, including control'lines leading from" the ground to the plane and normally employed to control ,.the fiight thereof acrank, means to rotate. said crank, I a pivotally mounted stop rest. normally engaged with said crank,.whee l assemblies linked to said crank, -wheels.;supported thereon, ,said control lines' being: operatively connected to said stop rest to disengage it'from the crank-whereby said crank rotating means-rotates, saidcrank to move said .wheel assemblies. to raise and -lower said wheels. I v v I HAROLD, H. SHARP.

REFERENCES CITED The following references are of record in the file .of this patent:

UNITED STATES- PATENTS Number Name Date 2,182,913 Brubaker Dec. 12, 1939 2,240,892 Meyer et al 'May,6, 1941 2,376,374 =Miles May22, 1945 2,384,193 -Platt Sept.-4, 1945 FOREIGN PATENTS Number Country .Date

T650377 Germany ..Qct..4,. 1937 

